ROCK CYCLE

The rocks under our feet seem permanent, but they are
constantly being changed. This process is called the rock cycle. Rocks exposed
on the Earth’s surface are slowly broken down into sediments by water,
ice, and wind. Meanwhile, new rocks are being created and recycled by forces in
the Earth’s crust and mantle, deep down under the
surface.

HOW ROCKS ARE FORMED

Older rocks on the surface are destroyed by erosion, or by being
pushed down into the crust and melted. New rock is formed as sediments are
compressed into sedimentary rocks, erupted magma cools and solidifies into
igneous rocks, and heat and pressure changes rocks underground into metamorphic
rocks.